The weathering was done using grey primer (to neutralise the bright cloth a little), white primer (to lessen the blackness of the elastic) and very watered down black acrylic paint rubbed over the surface of the boot with a cloth. I also put my hand inside and bent the boot (to mimic a walking effect) and lightly sprayed the creases with white to get a worn effect.
The spikes were made from 3 pieces of foamex (sintra) glued together, then I put some epoxy filler on the inside and pressed against the front of the boot sole (which I had applied masking tape to so as not to mess it up) this gave me the very snug fit. When dry I removed from the sole and filled any remaining gaps, sanded and painted. Weathering is just acrylic black again very watery and wiped away with a cloth.
I will try and post a bird's eye shot tomorrow...thanks for the nice comments.